Contrary to what is implied by the name, ringworm, or dermatophytosis, is not a worm at all! It is in fact a fungal skin infection caused by a group of fungi called dermtophytes. These critters can cause a small, round lesion on the skin accompanied by hair loss, scabbing and sometimes (but not always), itchiness. These lesions can occur in both dogs and cats, however in kittens and animals that have a suppressed immune system secondary to other illnesses, the lesions can cover large areas of the body. Cats, being tricky creatures, are able to carry the fungi in their fur and spread it to other animals without being infected themselves!